I've stolen Genghis' pre-takeoff brief (hope you don't mind!) that the student (and PPL on check) read out to me.'This is my take-off' etc, then the bit about 'if there is a problem on the ground, I will pull everything back and stop ahead'.' That could be ANY kind of problem and we discuss as many of the different types of problem you might have, from external issues, deer on the runway to internal, airspeed not as expected to oil on the windscreen. The next bit says 'if there is a problem in the air I will land ahead, turning no more than 30 deg either side of the centreline'.
There's NO WAY I'm teaching students to try and turn back - they lack the skills to make it work. I had a good friend and instructor who had 2 EFATOs. The 2nd was in his own Jodel and was a partial. He describes the 60 deg AOB turn he made at 500' and just scraped a downwind landing on the airfield. Any lesser pilot wouldn't have made it. I've tried turnbacks myself at various heights in a Cessna150 and at 45 deg AOB it only worked above 500'.
When I first start the long brief about PFLs we discuss the partial case, then practice it before moving on to the sudden, catastrophic failure. The question I ask is 'what is the first sign of partial engine failure?' The answer of course is a loss of altitude. You notice you've lost 500' and it's only when you go to apply more power you find out you can't. We then discuss options - 'land at the nearest suitable airfield'. One of the scenarios we discuss for the sudden total loss is your pax, wonders 'what's this big red knob for?' and is too embarrassed to admit they've pulled it back. Another is a recent AAIB report where the pilot admitted knocking off the mags with his knee. So, yes, the 'reason for failure' drills are very important. I teach work across the cockpit, touching each element as you go.Then it doesn't matter what type you are flying, you should cover all the essentials.
I've had one partial, on a go-around from a practice baulked landing. The throttle stuck at 2,000 RPM and wouldn't move either way. Fortunately, the pilot being checked out was very skilled so he flew while I analysed and planned. We had about 100' steady height and about 5kt above the stall. The plan was to fly a very careful circuit, then chop the mags on short final. As it happened, a massive tug on the throttle over the threshold released the corroded mechanism and we landed normally.
One last thing - below 1,000' AGL and not having restored normal power, if you've chosen a landing site don't even consider using the engine again, shut it down. That sudden burst of power on short final might just carry you into the housing estate instead of your nice short grass level field.
TOO